The present invention relates to a loudspeaker mounting frame for mounting a loudspeaker in a cabinet of an electronic device such as a radio, a television set or any other type of audio or audio/video appliance. It further relates to a loudspeaker and to a cabinet comprising such a mounting frame.
Conventionally, electromagnetic loudspeakers have a sound-radiating membrane of roughly frusto-conical shape, the outer rim of which is fixed to a rigid support ring. Webs extending from this support ring hold an electromagnet for driving the vibrations of the membrane in position at the small base of the frusto-conical membrane. In this support ring, a plurality of holes is formed. Such a loudspeaker is usually installed by placing its rear side on a carrier and driving screws through the holes into the carrier.
In order to protect the loudspeaker membrane from damage, it should be covered by a sound-transmission hood such as a stretched fabric or a perforated shell that will let the sound from the loudspeaker pass to the outside but will prevent outside objects from reaching the membrane and damaging it. The distance between the membrane and the hood should be kept small in order to prevent an unwanted dampening of trebles.
A loudspeaker assembly comprising a carrier and a hood as described above is complicated and expensive to produce.
It might therefore be contemplated to simplify such an assembly by using a stiff perforated shell as the protective hood and to provide receiving portions in this shell for receiving the shafts of screws by which the loudspeaker is screwed to the shell.
Such a solution is unsatisfying for various reasons. One reason is that the shaft receiving portions must be located between the shell and the support ring of the loudspeaker, whereby the distance between the shell and the loudspeaker is increased by the length of the shafts, at minimum, and reproduction of trebles is impaired. Another reason is that modern electronic appliances frequently have a freely curved shape. If such a shape is formed by moulding, bores of the shaft receiving portions must be parallel to the direction of displacement of the mould elements in the moulding process, because otherwise moulds having a high number of movable elements are required. However, this direction of displacement is not necessarily perpendicular to a mounting plane of the loudspeaker. If it is not, fixing screws will extend through the holes of the support ring at non-perpendicular angles, making the assembly awkward and irreproducible.